Characterization and evaluation of portable FT-NIR instrumentation for life science measurements

The current demand for versatile medical diagnostics has created a significant increase in the development of NIR spectroscopic techniques due to the relative transparency of body fluids and soft tissue in this spectral region. Specifically the non-invasive determination of blood substrates is a desirable measurement as a guide to the pathological condition of the patient, since blood forms the primary metabolic transport system for the body. There are well-defined needs for real-time near-infrared (NIR) monitoring instruments for in vivo clinical applications. This paper describes a compact and rugged FT-NIR instrument that has the potential to meet this need. A rapid software development environment was used to implement the active alignment, control and self-calibration algorithms. The current prototype has a spectral range of 500-2300 nm and collects a spectrum in 200 ms. The instrument has been validated with band-pass filters and water spectra. Hemoglobin (Hb) solutions and erythrocyte suspensions have also been measured. The well known water absorbance features around 1400 nm and 1900 nm have been observed along with Hb features around 550 nm and we have verified the published blood spectra.